Inhibition of fusion activity of influenza A haemagglutinin mediated by HA2-specific monoclonal antibodies
Inhibition of fusion activity of influenza A haemagglutinin mediated by HA2-specific monoclonal antibodies
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DOI：
10.1007/s00705-002-0932-1
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发表时间：
2003-03-01
影响因子：
2.7
通讯作者：
Kostolansky, F
中科院分区：
文献类型：
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作者：
Varecková, E;Mucha, V;Kostolansky, F
研究了甲型流感血凝素（HA）轻链（HA2）特异性7种单克隆抗体（mab）对其融合活性的影响。这些单抗是非病毒中和性的，在HA2糖共肽上确定了四个不同的抗原位点，相应的抗原表位归因于HA2上的序列延伸。经胰蛋白酶裂解和pH 5处理后，所有7个HA2表位的可及性均显著增加（X-31）。抗ha2单克隆抗体对融合过程的影响随后是表达HA前体的CHO细胞的细胞间融合、病毒-脂质体融合实验和病毒介导的溶血。MAb CF2直接与HA2的融合肽1-35结合，在所有三种融合抑制试验中均呈阳性，是唯一抑制CHO-X-31细胞多核形成的MAb CF2。另外两种属于相同抗原位点但不直接与融合肽结合的单克隆抗体抑制病毒与脂质体融合（EB12）或抑制溶血（BB8）。此外，MAb IIF4与125-175 HA2内不同的抗原位点结合也能抑制溶血。因此，HA的融合活性可能被抗ha2单克隆抗体抑制，主要是与融合肽结合或靠近融合肽的抗ha2单克隆抗体。这些抗体是研究流感病毒与细胞膜融合的有用探针。
The effect of seven monoclonal antibodies (MAbs) specific to the light chain (HA2) of influenza A haemagglutinin (HA) on its fusion activity was investigated. These MAbs, which are non-virus neutralizing, defined four distinct antigenic sites on HA2 glycopolypeptide and the corresponding epitopes were attributed to the sequence stretches on HA2. The accessibility of all seven HA2 epitopes significantly increased after trypsin cleavage and pH 5 treatment of the HA (X-31). The influence of anti-HA2 MAbs on the fusion process was followed by cell-cell fusion of CHO cells expressing precursor HA, virus-liposome fusion assay, and haemolysis mediated by virus. MAb CF2, which bound directly to the fusion peptide 1-35 of HA2, was positive in all three fusion-inhibition assays and was the only one inhibiting the polykaryon formation of CHO-X-31 cells. Two other MAbs belonging to the same antigenic site but not binding directly to the fusion peptide inhibited virus to liposome fusion (EB12) or inhibited haemolysis (BB8). Moreover, MAb IIF4 binding to distinct antigenic site within 125-175 HA2 inhibited haemolysis, too. Thus, fusion activity of HA may be inhibited by anti-HA2 MAbs, mainly those binding to or near the fusion peptide. These antibodies represent useful probes for studies of influenza virus to cell membrane fusion.